I have been playing this game recently. I personally Blame Chris Pirillo for telling me about it. It is Empire Avenue and if you like Social Media AND stock market games you are in for a treat!
So here is how it works: The site takes into account your “activity” across multiple Social platforms like Twitter and Facebook and even Blogs like this as well as Flickr and LinkedIn too! it then calculates your Activity and reach to come up with a score and dividend. ( I am over simplifying but it begins here) you can “buy” people and they can buy you. as you get bought the price goes up. You also get dividends for who you invest in and how they are doing. Its pretty addicting.
Check out my profile at http://www.empireavenue.com/geektechlive and sign up to invest in my show! the “Money” is called Eaves and you can buy trinkets or re-invest back into new people. I have met some really cool people on EmpireAvenue.com and I am having a blast playing the game. Try it, you will like it!